METHOD FOR FABRICATING THIN FILM TRANSISTOR

摘要

PURPOSE: A method for fabricating a thin film transistor(TFT) is provided to realize high-speed driving and high reliability by using a TFT in which a semiconductor layer is used as an active layer such that the semiconductor layer is crystallized by using continuous wave(CW) laser. CONSTITUTION: The semiconductor layer includes both a semiconductor layer of large crystal grain and a semiconductor layer of fine crystal grain, depending on the distribution of energy density, in the width direction of irradiated laser. Although the former shows proper electrical characteristics, the latter has poor electrical characteristics because the movement of electric charges is blocked in a poor condition in the grain boundary, resulting in inconvenience when used as an active layer for a transistor. A circuit is arranged so that all active layers of the TFT are formed from a semiconductor layer of large crystal grain.